Let's Make Robots!

Fan slow down

Hi. Does anyone know what happens when I slow down an AC fan with a diode to kill one phase? (I tried it, it slowed down, but I don't know will it keep working like that)
Please answer asap, I made an incubator which has 17 eggs in it now, and the airflow is bad in it, my 12V DC fan is too slow, and only stronger fan I have is too fast. Lives of little chickens are at stakes here, help please!

Basic electronic sets

Hello everyone.

I teach a robotic group, and last week we decided it was time to stop using kits and start doing something on our own. So we collected 20$ each and we need help at choosing the best stuff to buy.

We buy from local shops, 20$ is just so you know aproximatly how much we can spend.

We have tools already, we need just the electronic stuff. So i was thinking of getting:

3-dof biped

Hello. I had a plan of making a biped with 3 dof on each leg, so it could walk with lifting legs and not by sliding.I tried 2 different designs and none of them worked, it would fall down every time he tried to move the balance to one of the legs. Then I read an article that said that you can do what i want with 4 dof-s, but without the knee joint, and then movement looks weird becouse it has to swing his leg around for climbing and stuff like that.

So my question is, is it possible to make a 3dof biped that actualy walks?

Intellibrain problems

Hello everybody. I'm trying to get my intellibrain bot to comunicate with arduino via I2C, but I get some errors which I don't know how to debug. Google doesn't help at all. Here is what I get on my display when I turn on the program:
"Code: 20&97b6 
8d57 8d24 839d"
and after it shows that very shortly it turns the program off. It happens both when arduino is on and when it's off.

Many questions

Hi everybody. I have alot of questions and don't know how to find answers for them, so I would be very gratefull if you could tell me a precise location where to look for my answers.

So the questions are:

1. How to connect arduino severino to intellibrain board? I need to connect 3 of arduinos to one intellibrain only to send commands with coordinates so the arduinos can calculate the angles for servos to put the legs there, so i would only need to send 1 boolean to choose a leg and 3 integers to specify the coordinates.

Pulsing circuit

Hi everybody. I have an idea for some wierd stuff (I don't want to say what it is untill it works), but I don't know how to make it and I don't know how to google it.

I need a circuit that uses one DC power source, and a capacitator, and it can't have any switches, it has to work all the time the power is conected. It needs to charge the capacitator and when it's full send all the electricity it to the "Parts"/electronics. But "Parts"/electronics shouldnt get any power while capacitator is charging.


I dissasembled my broken TV and got alot of random stuff. Is there anything useful there? I found a diode and a IR reciever and alot of buttons and caps and resistors, and alot of stuff i cant identify yet, i will post pictures of it when i dissasemble it... What special parts should i look for? =D


Does anyone else break stuff to get parts from it?


I've been asigned a project to make a learning site with Intellibrain Bot tutorials. I have to explain only software side of it and I know most of it. But I have never teached anyone anything and I have never been realy teached robotics, all the stuff I learned is from examples and asking people on internet for specific problems.

So my question is in what order should I make it? How to teach people who never used a PC to program robots in Java?

Servo control in Java

Hello everyone. I am making my first robot, and it's going to be a hexapod.

I have trouble with finances so I don't have most of the parts yet, and I have to make things work with parts I have before I can get more money from my club for other stuff I need.

I have 3 CARSON CS-3 502015 servo motors and Intellibrain board (I've got it for robotics competition). I program it in Java becouse it doesn't support anything else, and compiler I use is RoboJDE.